The present invention is directed to an apparatus for mixing at least one flowable mass located in a container and positioned in a container carrier mounted on a rotatable support. The container carrier has an axis of rotation inclined inwardly relative to the central axis of the rotatable support. A drive rotates the rotatable support and also rotates the container carrier around its axis of rotation in a direction counter to the rotation of the rotatable support.
In many industries, crafts and trades there is the problem of supplying a plurality of mixtures rapidly at any time for performing different types of work. It is economically and technically impossible in such industries, crafts and trades to store a plurality of the required mixtures involving special colors and specific compositions, as well as for providing stability during storage. Accordingly, standard masses are usually purchased and modified as required. Such modification is effected by adding colored pastes, fillers, softeners, cross-linking agents, catalyzers and the like.
The prepared masses can be a single component or multi-component, liquid and pasty masses, used at the present time as bonding agents or as, encapsulating, casting, coating or masses. Such masses, as a rule, react after being applied and result in solid, gel-like or rubber-like products. Multi-component masses must be thoroughly mixed prior to application.
Apparatus for preparing such mixtures or masses have been known, particularly in dentistry, and comprise a rotatable support or arm rotating about an axis with a container carrier located in an outer peripheral region of the support and inclined towards the center of the support. The container carrier is driven around its axis of rotation, counter to the rotational direction of the rotatable support.
High centrifugal forces are generated by the high revolutions per minute of the rotatable support with the container located in the radially outer peripheral region of the support causing the mass being mixed to press against the outwardly oriented internal wall of the container. As the container rotates in the opposite direction, the somewhat stationary mass is peeled off. Due to the inclined position of the container, the mass slides off the free surface in a spiral shape and is deposited on or stripped from the mass. Since the container has a relatively large free surface on the side oriented towards the central axis of the support, new material is continuously peeled off the mass.
To perform the mixing process described above, the container cannot be completely filled. Depending upon the diameter and height as well as the inclination of the container, the maximum usable filling volume can vary to a great extent.
Known mixing apparatuses are suitable only for smaller quantities up to about 70 g. A counterbalancing element is located on the rotatable support directly diametrically opposite the container carrier, because of the developing centrifugal forces. The mass of the counterbalancing element is matched to the weight of the container carrier as well as to an average weight of the container and the mass to be mixed.
These known mixing apparatuses have the disadvantage of a limited mixing capacity and the counterbalancing element is never precisely matched to the container carrier along with the container and mass. As a result, there is an unbalanced behavior of the rotatable support, especially during the initial acceleration phase.